Installing:
  When installing Mageia 5 in UEFI mode, grub2 is the 
  default bootloader and will be installed and set up automatically. 
  If you have a dual mode 'BIOS', make sure you boot in UEFI mode and if
  using a USB stick for the install media, prepare the stick using isodumper,
  making sure to check the 'for UEFI' check box.
  
  If you already have other operating systems on the machne you will 
  already have an EFI System Partition (ESP). This should be detected 
  automatically and the moint point /boot/EFI will be suggested as it's
  mount point at the partitioning stage.
  
  --------------------------------------

  NOTES for MAC users: (these may be out of date but are left here as they may be useful)
  
  On Mac EFI systems there several options - see also
  https://help.ubuntu.com/community/UEFIBooting#Make_the_firmware_launch_GRUB2_.28U.29EFI_as_default
  After installing the grub2-efi rpm:

    0. prepare the EFI directory:

      boot_root=$(df /boot | awk '/^\// {print $6}')
      efi_dir=$(readlink -f ${boot_root}/EFI)  # will be /boot/EFI or /EFI
      mkdir $efi_dir

    1. If you have rEFIt:

      mv -T /boot/grub2 $efi_dir/grub2
      ln -s $efi_dir/grub2 /boot/grub2

    2. Otherwise if you are using the Apple bootloader:

      mv -T /boot/grub2 $efi_dir/BOOT
      ln -s $efi_dir/BOOT /boot/grub2

      mv /boot/grub2/{grub.efi,BOOTIA32.EFI}   # if on i386
      mv /boot/grub2/{grub.efi,BOOTX64.EFI}    # if on x86_64

  For further configuration see the above UEFIBooting wiki page.